Fumigating composition



. No Drawing.

Patented May 3, 1932 UNETED' STATES PATENT orrice m I. ROMIEUX, OF ELIZABETH, NEW JERSEY, ASSIGNOR T0 AMERICAN CYAN- MID comm, 01' NEW YORK, N. YQA CORPORATION 02 MAINE rumraarrnc comsrrron a carrier impregnated with hydrocyamc acid.

v The mixture magi or receptacles w" It has been'suggested in the past that liquid hydrocyanic acid may be absorbed in various porous bodies in powder or dust form, from which the hydrocyanicacid may be obtained by exposure to the air. However, the absorbents previously used are open to a number of ob ectiOns.

I have found that granular, calcined or burnt clayey or siliceo s products are particularly adapted as absor ents for hydrocyanic acid and have many advantages over the products of the prior art. v v

Specifically, I have found that a mass of granular, calcined clay brick of about 16 mesh and having absorbed therein about 45%, by weight, of hydrocyanic acid, gives a mixture suitable for fumlgation purposes. be placed in suitable cans ch are adapted to be maintained 1n a gas-tight condition until the contents are to be used. At such time, the can or like receptacle is opened and the desired quantity of material removed and placed in the fumigating room or chamber where it ives ofi gaseous hydrocyanic acid which perorms the desired fumigatin function.

The absorbent contemplate for use in the present invention is granular, calcined or.

urnt clay brick, with or without other calcined granular siliceous products such as the granular material obtained by crushing calcined brick made from infusorial earth, or this material alone. The calcined material is particularly valuable because of the porous nature of the material resulting from treatment at high temperatures during calcination or burning. This is one of the features which makes these substances good absorbents.

The granular absorbent is preferably of 6 to 20 mesh. Finer material than this is in the nature of a powder which, after the absorption of the iquid hydrocyanic acid, becomes wet and soggy with the resulting undesirable qualities apparent in handling the material. Materials of a large size than those contemplated for use in the present invention Application med. December 12, 1828. Serial No. 825,886.

are generally of such a nature that they do not absorb sufiicient liquid hydrocyanic acid to make them adaptable for read use; or when the larger sized materials 0 absorb suflicient hydrocyanic acid, the size of the materials prevents ready vaporization of the liquid hydrocyanic acid with the result that the fumigating time is necessarily much }greater in order to utilize all of the contained ydrocyanic acid. I have found that material in the form of granules of about 16 mesh is best adapted for the present invention.

The fumigating mixture should preferably contain between and hydrocyanic acid, by weight, 45% being the specific quantity most often utilized. The present invention is likewise adapted for use with other fumigants or mixtures.

In accordance with fumigating practice it is preferable to mix with the hydroc anic acid a material which volatilizes with t e hydroc anlc acid in use so as to give warning of t e presence of hydrocyanic acid in the fumi gating chamber. This warning material may be of any desired nature, for example, it has been found that chloropicrin is a material well adapted for use in the present composition. This material is employed in amounts of about 2 to 3%, based upon the weight of the entire fumigatin mixture.

Suitable stabihzing agents may be added a to the mixture to prevent decompositionof the hydrocyanic acid. Sulfuric acid, oxalic acid and the like are among those which may be employed for this purpose.

It is to be understood that the present invention is not limited to the exact details set forth since many modifications may be made without departing from the spirit and scope ticles of calcined brick, liquid hydrocyanic 35nd and chloropicrin absorbed in the granes. 4. A fumigant comprising granular particles of calcined clay brick of 6 to 20 mesh,

and liquid hydrocyanic acid absorbed in the granules.

5. A fumi ant com rising granular particles of calcined clay rick of 6 to 20 mesh,

and 30 to 50% of liquid hydroayanic acid absorbed in the granules.

'6. A fumigant comgrising granular particles of calcined clay rick of 6 to mesh, and to 50% of lifiuid hydrocyanic acid absorbed in the granu es.

7. A fumigant com rising granular par- 7 ticles of calcined clay rick of 6 to 20 mesh,

and of liquid hydrocyanic acid absorbed in the granules.

-8. A fumigant comprising calcined brick granules of about 16 mesh having absorbed therein 30 to liquid hydrocyanic acid and 2 to 3% chloropicrin, all by weight.

9. A fumigant comprising a mixture of granules of calcined clay brick and of infusorial earth'brick, and 30 to 50% of liquid hydrocyanic acid absorbed in the granules.

In testimony whereof, I have hereunto subscribed my name this 11th day of December,

' CHARLES J. ROMIEUXP 

